This invention relates to a Y connector for use in an angioplasty procedure.
The angioplasty procedure for repair of a blood vessel has been known for many years. The procedure provides an opportunity to open up a clogged blood vessel, particularly a coronary artery, and thus avoid the expense and trauma of bypass surgery.
The procedure involves the insertion of a large guide catheter up to the blood vessel to be repaired. A Y connector is attached to the free end of the guide catheter by means of a rotatable coupling of the type disclosed in U.S. Pat. No. 4,254,773. The Y connector has a main passage through which the dilatation catheter is inserted. The Y connector has a branch passage to which a multiport manifold is connected. One port of the manifold is connected to a blood pressure monitor of the type disclosed in copending application Ser. No. 07/072,909, filed July 14, 1987. Another port of the manifold is connected to a supply of contrast media which is a fluid injected into the blood vessel enabling a real time observation of the blood vessel through X-ray.
At a minimum, the angioplasty procedure involves the following steps:
The guide catheter is inserted through a blood vessel in the patient's arm or leg into the heart.
A blood pressure monitor is connected to the Y connector to provide a continuous monitor of a patient's blood pressure.
The contrast medium is introduced into the blood vessel so that the blockage of the blood vessel can be identified.
A dilatation catheter having a balloon on its free end is introduced through the main passage of the Y connector. When the end of the dilatation catheter is in place in the area of the blockage caused by a growth of placque, a saline mixture is injected through the dilatation catheter to the balloon on its end to inflate it. As the balloon is inflated, it ruptures the placque in the coronary artery so as to permit normal or at least improved blood flow.
The dilatation catheter is thereafter removed and contrast medium again introduced and a post dilatation arteriogram is made to check the success of the procedure.
Thereafter, the dilatation catheter may be reintroduced. It may be desired to use a larger catheter. It may be desired to introduce a small guide wire instead of a dilatation catheter.
In any event, more than one insertion and withdrawal through the main passageway is normally required to complete the angioplasty procedure.
Blood under normal body pressure is of course in the main passageway just as it is in the branch passageway where it is being continuously monitored. The blood will tend to escape through the main passageway as by directly flowing through the main passageway when a catheter is removed or by flowing by the catheter when it has been inserted.
It is known in the prior art to provide sealing against the escape of blood through the main passageway of the Y connector. One seal is an adjustable Tuohy-Borst type valve. The Tuohy-Borst valve includes an O-ring-type element seated in a socket forming part of the main passage. A cap threaded on the end of the passage contains a spigot which compresses the O-ring when the cap is rotated to drive the spigot inwardly. The compression closes down the opening in the O-ring around the catheter to prevent "flow-by." When the catheter is absent, the O-ring can be closed down enough to completely close off the opening in the main passage.
An alternative form of seal employs a membrane having a small hole of about 0.045" diameter. Catheters of a slightly larger outside diameter than the hole are inserted through the membrane, the membrane forming the seal against "flow-by."
Neither Y connector seal is completely satisfactory. The Tuohy-Borst has the disadvantage that it requires manipulation in order to match the size of the opening in the ring to the outside diameter of the dilatation catheter. If the cardiologist does not tighten it sufficiently, blood will flow by the valve. If it is too tight, the catheter can be inserted only with difficulty because of the friction or the catheter can be crushed.
The membrane-type seal eliminates the foregoing disadvantages of the Tuohy-Borst valve but has its own disadvantages. It cannot be completely closed off when a catheter is removed. Under those circumstances, when the dilatation catheter is removed, the Y connector has to be removed and the manifold connected directly to the rotator. During this step, there is nothing to prevent the blood from flowing through the guide catheter and into the surgical area. Further, the smaller catheters, for example 0.036" O.D., cannot properly be sealed by a membrane that has a hole that is 0.045" diameter.